Human blood vessels often become occluded or blocked by plaque, thrombi, other deposits, or emboli which reduce the blood carrying capacity of the vessel. If the blockage occurs at a critical place in the circulatory system, serious and permanent injury can occur. Medical intervention, such as an angioplasty, is usually performed when significant occlusion is detected. For example, laser based catheter devices are often used to ablate the occlusions in the vessels.
Treatment of vascular lesions is made difficult by lesion morphology that can contain a variety of plaque types ranging from soft to bone hard. Different atherectomy tools have been developed to deal with different types of plaque. Performance with one plaque type is typically sacrificed for improved capability with another plaque type.